Orca works with the assistive technology service provider interface (AT-SPI). The GNOME GTK+ toolkit, the Java platform's Swing toolkit, SWT, OpenOffice/LibreOffice, Mozilla, and WebKitGtk are among the AT-SPI supported toolkits and applications. Support for KDE Qt toolkit is also being looked at.

Orca, since the GNOME 2.16 release, is available as part of the GNOME platform and continues to be provided by default on operating system distributions, such as Open Solaris, Fedora, and Ubuntu.